Wheelchair users benefit from exercise through reduced risk of cardiovascular disease, better functioning in the activities of daily living, increased self-esteem, and improved rehabilitation outcomes. Unfortunately, wheelchair users report that the exercise options they have provide little motivation to exercise. There is a need to create environments in which people in wheelchairs are able and motivated to exercise. The GAMECycle addresses this need by merging exercise with videogame playing. In Phase I, lab testing demonstrated that the GAMECycle allows users to maintain target aerobic training levels, and was perceived by users as fun and as likely to enhance their motivation to exercise more frequently. In Phase II, we will further refine the design of the GAMECycle by 1) improving the stability of the system to minimize vibrations even when exercising vigorously, 2) maximizing the user's capabilities within the videogame context and expanding the variety of videogames with which the system is compatible, 3) enhancing the extent to which the system can be modified to meet the needs of the user, and 4) readying the system for commercial production. We will also place the refined prototype in rehab facilities and in the homes of end-users for a four-month trial for more extensive testing and evaluation of the GAMECycle, as compared with a standard arm-ergometer. The design improvements coupled with extensive off-site testing will insure the commercial viability of the GAMECycle, both as a product for individual in-home use, and as a product for institutions interested in better meeting the needs of their clients.